Flashcards in CE 10224A - Science for CE (Biology) Deck (75)
What are considered the building blocks of life?
Amino acids / proteins (catalysis, DNA replication, enzymes, transport)
Nucleic acids (code, transmit and express genetic info)
Carbohydrates (energy, structure, nutrition and genetic molecules)
Lipids (energy and structural appliances)
Lignin (in plants)
What are (3) types of microorganisms?
Cellular (bacteria, archaea and eukarya)
Viruses (non cellular microbes)
Prions (infectious molecules - aren’t organisms as they have no genetic material)
How do gram positive and negative bacteria differ?
Gram positive bacteria have many layers of peptidoglycan. This means they can retain the stain.
Gram negative have a few layers of peptidoglycan, and an outer membrane made up of lipopolysaccharides, lipoproteins and phospholipids.
It’s outer membrane is also permeable due to the presence of porins.
What is a hypotonic, isotonic and hypertonic solution?
Hypotonic - the solution has a lower amount of solutes
Isotonic - the solution has the same level of solutes
Hypertonic - the solution has a higher amount of solutes
What’s a uniporter?
A membrane carrier protein.
It binds to one substrate molecule at a time and is involved in facilitated diffusion.
What’s a symporter?
A membrane protein which allows molecules to be transported in the same direction at the same time.
This requires entropy
What’s an antiporter?
A membrane protein and cotransporter which transports two or more different molecules in opposite directions.
What does the nucleus do?
It contains genetic info - chromatin threads: DNA, RNA and protein.
Surrounded by porous nuclear envelope - contains importin and exportin pores.
What do ribosomes do?
Are site of protein synthesis.
Free ribosomes produce protein for the cytoplasm
Bound ribosomes produce protein for the membrane or for use outside of the cell.
They’re 15- 20 nm in diameter, comprising two sub-units: a large one (60S) and a small one (40S).
Each sub-unit contains rRNA and protein.
(S is the Svedberg unit – related to size and shape measures how fast a particle falls out of solution during centrifugation)
What’s does the endoplasmic reticulum do?
SER - lipid synthesis
RER - protein synthesis
What do lysosomes do?
They contain a range of digestive enzymes, called hydrolayses, which can break down all biochemicals.
What does the Golgi apparatus do?
Tag and package molecules, to send them where needed.
What do chloroplasts do?
Perform respiration in photo-synthetic eukaryotes – responsible for energy recovery from light.
Contain a characteristic internal membrane structure called the thyllacoids, which houses the photochemical reaction centres – chlorophylls.
What do vacuoles do?
Used for transporting and storing nutrients, metabolites and waste products. Act similarly to lysosomes.
Maintains cell shape and size through turgor pressure. (The osmotic pressure that stops the plant wilting.)
Major compartment inside a plant cell, surrounded by membrane called the tonoplast.
Typically occupy more than 30% of the volume of the cell
What are photoautotrophs?
Organisms that carry out photosynthesis.
They get their energy from light and (auto) get their CO2 from air.
What are photoheterotrophs?
Organisms that use light for energy, but cannot use carbon dioxide as their sole carbon source.
They use organic compounds from the environment to satisfy their carbon requirements
What are chemoautotrophs?
Organisms that obtain energy by the oxidation of electron donors in their environments.
Cells that create their own energy and biological materials from inorganic chemicals.
What’s a chemoheterotroph?
An organism which derives its energy from chemicals, and needs to consume other organisms in order to live.
What’s an exergonic reaction?
A reaction which gives off energy e.g. catabolism.
What’s an endogonic reaction?
Reactions which take in energy e.g. anabolism.
What acts as the electron donor and acceptor in photosynthesis?
H20 is the electron donor
NADP+ is the electron acceptor
What is used and produced in the Calvin cycle (photosynthesis)?
- 3 molecules of CO2
- 9 molecules of ATP
6 molecules of NADPH
- 1 molecule of glyceraldehyde 3 phosphate
What is an electron donor?
Chemicals (reducing agents) which get oxidised and donate electrons to another compound (they’re typically organic molecules).
Examples include water, sugar fats.
What is an electron acceptor?
A molecule (oxidising agent) that gets reduced by accepting electrons from other molecules.
Examples include oxygen, nitrates, NAD+ and NADP+.
What are examples of chemoheterotrophs?
Most heterotrophic bacteria
(Denitrifying bacteria and Methanogens under anaerobic conditions)
What acts as the electron donor and final electron acceptor under aerobic respiration for chemoheterotrophs?
Electron donor: organic substances such as fats, sugars and organic acids
Electron acceptor: oxygen
What acts as the electron donor and final electron acceptor under anaerobic respiration for chemoheterotrophs?
Electron donor: organic substances such as fats, sugars and organic acids.
Electron acceptor: CO2, nitrates (NO3-) and sulphates (SO4 2-)
What are examples of chemoautotrophs?
What acts as the electron donor and final electron acceptor under anaerobic respiration for chemoautotrophs?
Electron donor: hydrogen, nitrites (NO2 -), ammonium (NH4+), hydrogen sulphide (H2S), thiosulfate (S2O3 2-)
Electron acceptor: CO, nitrates (NO3-), sulfates (SO4 2-)